Fine needle aspiration biopsy of cystic benign lymphoepithelial lesion of the parotid gland in patients at risk for the acquired immune deficiency syndrome

Cystic benign lymphoepithelial lesion (BLL), a previously rare lesion of the parotid gland consisting of marked lymphoid hyperplasia with accompanying squamous-lined cysts, has recently been described in patients with the acquired immune deficiency syndrome (AIDS) or AIDS risk factors. Thirteen fine needle aspiration (FNA) samples of parotid gland masses from patients with AIDS (one case), AIDS risk factors (five cases) or denial of AIDS risk factors (two cases) and a histopathologic diagnosis of BLL were examined. The FNA features that correlated best with the histopathologic findings were (1) a heterogeneous lymphoid population, (2) scattered single and/or clustered foamy macrophages and (3) superficial and/or anucleated squamous cells. Most aspirates showed some combination of these three components. The differential diagnostic considerations, the clinical and radiologic correlations and the relationship of this lesion to HIV infection are discussed. Patients with parotid masses whose aspirates consist of some combination of squamous cells, lymphocytes and foamy macrophages should be questioned for possible AIDS risk factors.     

Simple method for separating the chlamydoconidia of Candida albicans from its mycelium

Different physical and chemical methods were used to detach the chlamydoconidia of Candida albicans from its mycelium. The action of concentrated H₂SO₄ acid for a 4-min period on cultures lysed both the mycelium and the outer but not the inner wall layer of the chlamydoconidia.The sulfuric acid procedure is recommended as the best method to obtain mycelium free chlamydoconidia because of its simplicity, rapidity and low cost.     

Characterization of a monoclonal antibody to human proacrosin and its use in acrosomal status evaluation.

Among the monoclonal antibodies (MAb) selected after immunization of mice with a detergent-insoluble fraction from human spermatozoa, MAb 4D4 was found to stain in immunofluorescence the principal part of the acrosome of human spermatozoa. Acrosome reaction induced decreased and spotty 4D4 immunofluorescence staining. Immunoelectron microscopy before or after embedding revealed that the epitope defined by MAb 4D4 was sequestered in the anterior acrosomal matrix and, after the acrosome reaction, remained partly bound on matrix elements attached to the inner acrosomal membrane. Western blot analysis of sperm extracts showed that the epitope defined by MAb 4D4 was located on a 55 KD polypeptide in whole cells and on 55 and 50 KD polypeptides in non-ionic detergent fractions. Human proacrosin-enriched fraction obtained by FPLC purification exhibited several proteolytic activities against gelatin in gel enzymography: a 50 KD major band and two minor bands in the 20-30 KD area; the 50 KD polypeptide reacted with MAb 4D4 in Western blots. Furthermore, the 4D4-immunoprecipitated polypeptide from sperm extract showed that the 50 KD band exhibited proteolytic activity with an optimal pH at 8.0 that was strongly inhibited by soybean trypsin inhibitor and ZnCl2. MAb 4D4 also reacted with the acrosome of the monkey Macaca fascicularis but not with the acrosome of any of the other non-primate mammalian species examined so far. Various shape defects of the acrosomal principal region were revealed by 4D4 labeling of spermatozoa with head anomalies from infertile patients. MAb 4D4 also recognized proacrosin in paraffin-embedded human testis sections. These data make the monoclonal antiproacrosin antibody 4D4 an efficient tool for evaluation of the acrosomal status of human spermatozoa and spermatids.     

Insecticidal effectiveness ofMammea Americana (Guttiferae) extracts on larvae ofDlabrotica Virgifera Virgifera (Coleoptera:Chrysomelidae) andTrichoplusia Ni (Lepidoptera:Noctuidae)

Seed and leaf extracts ofMammea americana (mamey apple) have a historical use as a biopesticide with the active components previously characterized. We reexamined the utility of this natural bioinsecticide in light of existing sources of material as a by-product of the fruit processing industry. Our results addDiabrotica virgifera virgifera andTrichoplusia ni to the list of insects which are susceptible to the insecticidal ingredients ofM. americana and confirms earlier reports of activity againstBlatella germanica, Periplaneta americana, andPlutella xylostella. We report LD5Os for crude hexane extracts ofM. americana leaves and seeds againstT. ni. These materials represent renewable sources of bioinsecticides for agriculture, and should regenerate interest in coumarin-type compounds for novel pesticidal action.     

The combined role of glaciation and hybridization in shaping the distribution of genetic variation in a Patagonian southern beech

Aim The distribution of the genetic variation in long‐lived species is a combination of both, historical and current processes. In Nothofagus nervosa (Phil.) Dim. et Mil., the possible existence of multiple glacial refugia, the unidirectional gene flow along fragmented areas and the natural hybridization with the related species Nothofagus obliqua (Mirb.) Oerst. highlights as the most important factors responsible for modelling its genetic structure. The present study aims to find out the relative importance of these evolutionary processes in determining the distribution pattern of the genetic variation in N. nervosa. Location The study was carried out in north‐western Patagonia, Argentina. Twenty populations covering the entire distribution range of N. nervosa in Argentina were analysed. For comparison purposes, three populations from Chile were also included. Methods Genetic variation was detected using isozyme gene markers; diversity and differentiation parameters were calculated. A cluster analysis was performed and the correlation between genetic and geographical distances was tested. Results Levels of genetic variation were relatively high given the small distribution range of the species in Argentina. Genetic and geographical distances were not correlated and a longitudinal trend in the genetic variation was evident. Hotspots of diversity with rare and private alleles were observed among western populations, while hybrid seeds were found almost exclusively among eastern populations. Main conclusions The higher level of diversity observed in western populations could be related with the location of glacial refugia. Furthermore, it should also reflect low levels of gene flow given the eastward unidirectional winds. On the contrary, ancient and current interspecific hybridization processes would mainly cause the particular genetic constitution of the eastern populations. Evidence is presented supporting that glaciations and hybridization were the main factors shaping the distribution of the genetic variation in N. nervosa.     

Sodium cholate-induced changes in the conformation and activity of rat pancreatic cholesterol esterase

Pancreatic cholesterol esterase (CEase) regulates dietary cholesterol absorption and is activated in the presence of trihydroxy bile salts while remaining inactive monohydroxy bile salts. CEase from rat pancreas has been purified by ammonium sulfate precipitation, hydroxylapatite chromatography, and gel filtration on Sephacryl S-200/S-300 columns connected in series, and its homogeneity and Mr (55,418 +/- 288) have been determined by sedimentation equilibrium centrifugation. The effects of tri-, di-, and monohydroxy bile salts on the conformation of the purified enzyme in buffer solution and in an in vitro assay system were studied by circular dichroism spectropolarimetry. The CD spectrum of the enzyme in solution shows a curve shape suggestive of an alpha-helicity, but low mean residue ellipticity (MRE) values may indicate an important beta-turn contribution. Sodium cholate, a trihydroxy bile salt, induces a decrease in the negative MRE values of the enzyme in solution at bile salt concentrations of 70-100 nM, with no further spectral changes at concentrations as high as 1 mM. Sodium cholate concentrations higher than 1 microM also induce an increase in the enzyme's negative MRE values under activity assay conditions, which reverts toward its original value once the reaction reaches equilibrium. These latter changes are interpreted as induced by substrate binding to the enzyme followed by partial substrate depletion after the reaction reaches equilibrium. Sodium deoxycholate, a dihydroxy bile salt, induces unstable transient increases and decreases in the MRE values of CEase in buffer solution and under activity assay conditions. These changes are bile salt concentration-dependent and may reflect self-association of the protein. Sodium taurolithocholate, a monohydroxy bile salt, does not affect the CD spectrum of CEase, and neither the di- or the monohydroxy bile salt activates the enzyme.     

Teleconference versus Face-to-Face Scientific Peer Review of Grant Application: Effects on Review Outcomes

Teleconferencing as a setting for scientific peer review is an attractive option for funding agencies, given the substantial environmental and cost savings. Despite this, there is a paucity of published data validating teleconference-based peer review compared to the face-to-face process.Our aim was to conduct a retrospective analysis of scientific peer review data to investigate whether review setting has an effect on review process and outcome measures.We analyzed reviewer scoring data from a research program that had recently modified the review setting from face-to-face to a teleconference format with minimal changes to the overall review procedures. This analysis included approximately 1600 applications over a 4-year period: two years of face-to-face panel meetings compared to two years of teleconference meetings. The average overall scientific merit scores, score distribution, standard deviations and reviewer inter-rater reliability statistics were measured, as well as reviewer demographics and length of time discussing applications.The data indicate that few differences are evident between face-to-face and teleconference settings with regard to average overall scientific merit score, scoring distribution, standard deviation, reviewer demographics or inter-rater reliability. However, some difference was found in the discussion time.These findings suggest that most review outcome measures are unaffected by review setting, which would support the trend of using teleconference reviews rather than face-to-face meetings. However, further studies are needed to assess any correlations among discussion time, application funding and the productivity of funded research projects.